(a) Field of the Invention
This invention relates to a tachometer generator having a brush carrier of insulating material fastened to the tachometer housing at the end face on which at least two brush holders, acting with the carrier, form brush guides. A carbon brush provided with a coil spring is inserted into the brush guide and the coil spring is braced against an abutment of the brush holder. An electric wire can be connected to the brush holder.
(b) Description of the Prior Art
Tachometer generators of this general type are assembled to commerically available DC motors. In such tachometer generators, a clamp-shaped brush holder is riveted to the brush carrier and the carbon brush is guided between the clamp bracket and the brush carrier. Radially extending strips which are angled off toward each other at their free ends are formed on the clamp bracket. The ends of the two angled-off strips overlap. There is an axial gap between the angled-off ends and the brush carrier into which an angled-off projection of a contact plate connected to the coil spring extends, securing the coil spring in the axial direction. In this brush arrangement, the electric current is transmitted via the contact plate of the coil spring to the angled-off end of the strips of the brush holder and from there, to an electric wire connected to the brush holder. The contact plate is pushed by the force of the spring against the angled-off ends of the strips, serving as an abutment, and contact is thus established.
It is an object of the invention to provide a tachometer generator in which the brush holder can be assembled more easily than that just described and in which at the same time, the contact between the abutment of the brush holder and the coil spring is improved.